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PubMed1998

[Ultrastructural localization of lipid peroxides in the eye. Presentation of a new method].

UNLABELLED: Lipid peroxidation is considered a prominent feature of age-related retinal degeneration. It is known that lipid peroxides can oxidize benzidine. This property was used to localize lipid peroxides ultrastructurally in the retina. METHODS: (1) Lipid peroxides were formed by incubation of linoleic acid with lipoxygenase from soybean, separated by thin layer chromatography and incubated with tetramethylbenzidine. (2) Lipid peroxides were formed by incubation of porcine retinae with soybean lipoxygenase in an oxygensaturated atmosphere. For ultrastructural localization, isolated retinae with and without enzymatically synthesized lipid peroxides were fixed with 2% glutaraldehyde, incubated with 0.5 mg/ml tetramethylbenzidine and embedded for electron microscopy. (3) Eye cups from Syrian golden hamsters were treated in the same way except for incubation with lipoxygenase. The hamsters were kept under constant illumination (1000 lux) for 12 h to enhance lipid peroxidation. RESULTS: (1) Tetramethylbenzidine was oxidized by linoleic acid peroxides. (2) In the isolated retinae of pigs lipid peroxides became visible as electron-dense structures in the rod outer segments (ROS) after treatment with lipoxygenase and were lacking in the other parts of the retina. Without treatment with lipoxygenase lipid peroxides were only infrequently seen in ROS. (3) In the eyes of light-exposed hamsters, electron-dense reaction products of lipid peroxides were particularly prominent between the basal infoldings of the RPE and within the apical parts of the ROS. CONCLUSION: Light or enzymatically induced lipid peroxides can be localized ultrastructurally due to their ability to react with tetramethylbenzidine and osmium in the absence of H2O2 to an electron-dense reaction product. Lipid peroxides seem to be removed from the RPE via Bruch's membrane and blood vessels. Disturbance of this pathway may enhance lipofuscin or drusen formation.

Animals↗
PubMed2002

Pre-embedding immunogold labeling of TUNEL stain enables evaluation of DNA strand breaks and ultrastructural alterations in individual cells of neuronal tissue.

In the brain apoptosis may occur as a physiological phenomenon during periods of programmed cell death as well as under pathological conditions such as ischemia, trauma, tumor, and degenerative diseases. While the definition of apoptotic cell death was originally based on ultrastructural alterations, the detection of DNA double-strand breaks has become an important feature in studies of apoptosis. Currently, the terminal transferase-mediated dUTP nick-end labeling (TUNEL) procedure is widely used for detection of apoptotic cell death. However, there is a growing body of evidence to suggest that the TUNEL staining does not label apoptotic alterations exclusively. Therefore, a new staining procedure was developed combining TUNEL methodology with pre-embedding nanogold labeling to detect DNA double-strand breaks in individual cells by electron microscopy and assess the accompanying ultrastructural alterations. In vitro DNAse-treated vibratome sections (thickness, 20 micro m) from normal adult rat brains were used to develop the staining procedure consisting of the following steps: (i) TUNEL staining of free-floating vibratome sections using fluorescein isothiocyanate (FITC)-labeled UTP, (ii) conversion of the fluorescence signal into an electron-dense signal using an anti-FITC antibody coupled with ultrasmall (diameter, 0.8 nm) gold particles followed by silver enhancement, and (iii) osmification, embedding in Spurr resin and cutting of ultrathin sections. Early postnatal brain tissue was used to study physiologically occurring apoptotic cell death. Under these conditions different patterns of gold staining were observed probably representing different states of cellular decay along the apoptotic avenue. Severe focal brain ischemia was studied as a pathological situation in which intense TUNEL staining occurs. Under these conditions TUNEL labeling of cells was regularly observed in conjunction with ultrastructural alterations indicative of necrosis. These results suggest that under pathological conditions apoptosis and necrosis are not mutually exclusive mechanisms but rather may occur concurrently along a continuum in which cell death occurs.

Animals↗
PubMed2003

Immunohistochemical and ultrastructural study of chordoid glioma of the third ventricle: its tanycytic differentiation.

A chordoid glioma in the third ventricle was studied immunohistochemically and ultrastructurally. In this report, special attention is paid to the histogenesis in relation to the pathological appearance and unique anatomic location of this tumor. Light microscopic and immunohistochemical findings were similar to those reported previously. Ultrastructurally, microvilli were frequently seen, but three types of abnormal cilia were rarely observed. Basement membrane around the tumor cells and microvessels was extensive. Poorly to moderately developed intermediate (adherent) junctions were frequently seen. Resemblance of these ultrastructural features of the tumor to embryonic tanycytes suggests the tanycytic differentiation of chordoid glioma. Neuroradiologically, all of the previously reported cases of chordoid gliomas seem to arise in the anterior part of the third ventricular floor. This region includes the lamina terminalis, infundibular recess and median eminence, which corresponds to a tanycyte-rich area. These findings suggest a tanycytic origin of chordoid glioma.

Adherens Junctions↗
PubMed1997

Ultrastructural concomitants of hypoxia-induced angiogenesis.

Prolong hypoxia results in structural and functional adaptive responses to improve tissue oxygen delivery. Structural changes within the brain include vascular proliferation and elongation. The aim of the current study was to investigate whether ultrastructural changes in capillary walls also occur as part of the adaptive response. Adult rats were exposed to 2 or 3 weeks of moderate hypobaric hypoxia at 0.5 atmospheres and their cerebral microvasculature examined using quantitative ultrastructural methods. We found that hypoxic rats had an 18% increase in their brain capillary diameter but no change in endothelial wall thickness, basement membrane thickness, or coverage of the endothelial wall by pericytes. The increased diameter of cerebral capillaries may plan an important role in decreasing the resistance to capillary perfusion which is brought about by the increased erythrocyte fraction in the blood of hypoxic rates. Ultrastructural features relevant to the blood-brain barrier were maintained in hypoxic rats. Pericytes, that are thought to form a second line of defense in the blood-brain barrier, maintained their numerical and size relationships to the endothelial cells. Endothelial junctions were unchanged and endothelial vesicles were somewhat lower in density than normal at 2 weeks of hypoxia, but had regained their normal density by 3 weeks. Mitochondria of the brain capillary endothelial cells maintained normal numerical and volume densities in hypoxia, but the mitochondria of the surrounding neuropil were decreased significantly by about 30%.

Animals↗
PubMed1997

Ultrastructural changes in rat locus coeruleus induced by chronic opioids.

The locus coeruleus (LC) is a major noradrenergic nucleus in the brain. The activity of the LC neurons is chronically regulated by opioids. So far, very little is known about the morphological changes induced by chronic treatment with opioids. In the present study, the effects of chronic treatment with morphine and dihydroetorphine, a new narcotic analgesic with lower physical dependence potential than morphine, were investigated on the ultrastructure of the rat LC. Rats received saline or increasing doses of morphine or dihydroetorphine for 5 days by twice daily subcutaneous injections. Withdrawal was precipitated in half of the opioid-treated rats by a single intraperitoneal injection of naloxone 4 h after the last injections of opioids. The ultrastructure of the LC was examined by electron microscopy. Results showed that chronic morphine treatment induced a marked injury to the LC neurons. The primary changes in the cell body were the indentation of nuclei, the fragmentation and degranulation of rough endoplasmic reticulum, as well as the disaggregation of polyribosomes. Myelinoid bodies were seen in the processes. An accumulation of presynaptic vesicles was observed in some of the terminals which formed synaptic junctions with the LC neurons as compared to the normal controls. Naloxone-precipitated withdrawal from morphine did not stop the morphine-induced injury on the LC neurons except that less accumulation of presynaptic vesicles occurred. Chronic dihydroetorphine treatment only induced a slight change in the ultrastructure of the LC neurons. These results indicate that the LC neurons are more vulnerable to chronic treatment with morphine than to that with dihydroetorphine.

Analgesics↗
PubMed1997

Central neurocytoma: an immunohistochemical, ultrastructural and cell culture study.

To clarify the histogenesis and differentiation potential of central neurocytoma, a pathological investigation of seven tumors from three patients was conducted using immunohistochemistry and ultrastructural analysis in addition to systematic in vitro studies. Six tumors were studied immunohistochemically and five were examined ultrastructurally. All cases that were immunostained were positive for synaptophysin in nuclear-free neuropil islands. In five tumors, a few tumor cells, in addition to reactive astrocytes, were positive for glial fibrillary acidic protein (GFAP). Vimentin staining was also positive in a few tumor cells of five specimens. Neurofilament staining was always negative. All cases for which ultrastructure was examined showed various synaptic abnormalities. Cultured cells were subdivided into three distinct tumor cell types: neuronal cells which stained for neurofilament proteins with neurosecretory granules; small flat undifferentiated cells with a high nuclear-cytoplasmic ratio and scant cytoplasmic organelles; and small round or multipolar astrocytic cells with 10-nm intermediate filaments which stained for GFAP. Our tissue culture studies disclosed that cultured neurocytoma cells form a cellular mosaic similar to subependymal plate layers that are composed of mitotically active cells, neurons and glia.

Adult↗
PubMed1998

Ultrastructural and permeability features of microvessels in the olfactory bulbs of SAM mice.

The ultrastructural features of microvessels showing increased permeability to intravenously injected horseradish peroxidase (HRP) were examined in the olfactory bulbs of senescence-accelerated prone mice (SAMP8), which showed age-related deficits in learning and memory, and senescence-accelerated resistant mice (SAMR1), which did not show the age-related deficits. HRP was visualized with tetramethyl benzidine (TMB) and diaminobenzidine (DAB) for light and electron microscopic examination, respectively. In the olfactory bulbs of 13-month-old SAMP8 mice, the staining reaction with TMB for HRP appeared in the neuropil of central area (granule cell layer and subependymal layer), in the pia mater and in the vascular wall. Some vessels located in the central area showed several changes observed at the ultrastructural level. The cytoplasm of the endothelial cells, especially in the arterioles, was segmentally thickened and contained numerous vesicles and vacuoles, some of which were HRP positive. The endothelial cell surface was occasionally undulated with microvillous protrusions. Membranous inclusions within the basal lamina, suggesting the cellular (presumably pericytal) degeneration, were frequently observed, especially in venules. The collagen deposits were occasionally observed in the subendothelial space of some vessels. Perivascular cells with vacuolated inclusions or lipid-like droplets were present around some vessels in the central area of the olfactory bulbs of aged SAMP8 mice. On the other hand, in the microvessels located in the areas negative for HRP-TMB reaction, except the vessel walls, the cytoplasm of the endothelial cells with smooth luminal surface was flattened and some vesicles located there contained HRP-DAB reaction product. Weak staining reaction with TMB for HRP appeared also in the central area of the olfactory bulbs of 3-month-old SAMP8 mice and 3- and 13-month-old SAMR1 mice. The cytoplasm of the endothelial cells in the olfactory bulbs of these mice was focally thickened and contained some cytoplasmic vesicles. Occasionally, the endothelial cell surface was moderately undulated with few microvillous protrusions. Membranous inclusions within the basal lamina were not observed in these animals. These findings indicate that the endothelial cells and pericytes in some vessels located in the central area of the olfactory bulb of aged SAMP8 mice, which show staining reaction with TMB for HRP, are ultrastructurally changed, suggesting their altered functions.

Age Factors↗
PubMed1999

Bunina bodies in amyotrophic lateral sclerosis on Guam: a histochemical, immunohistochemical and ultrastructural investigation.

An investigation of Bunina bodies is important when studying the pathoetiology and pathomechanisms involved in amyotrophic lateral sclerosis (ALS). It may serve as a clue essential for the study of the pathogenesis of Guamanian amyotrophic lateral sclerosis (ALS-G), and it may provide a means of answering the question of whether ALS-G is the same disease as classical ALS or a different entity. In ALS-G, however, no precise histochemical, immunohistochemical, or detailed ultrastructural examination has been published to date. To elucidate the pathological differences/similarities of Bunina bodies between classical ALS and ALS-G, we performed histochemical, immunohistochemical, topographic and ultrastructural examinations. Histochemically, hematoxylin and eosin, Masson's trichrome, methylgreen-pyronin, phosphotungstic acid-hematoxylin, Klüver-Barrera, Bodian and periodic acid-Schiff staining were utilized. Immunohistochemical examination was performed using antibodies for cystatin C, ubiquitin, Tau-2, Cu/Zn superoxide dismutase, phosphorylated neurofilament and glial fibrillary acidic protein. Histochemical findings were consistent with those previously described for classical ALS. The immunohistochemical study showed that in ALS-G Bunina bodies were intensely labeled by an anti-cystatin C antibody. Topographic examination demonstrated that Bunina bodies were distributed in the spinal anterior horns and Clarke's column in the spinal cord. Ultrastructurally, Bunina bodies were composed of electron-dense amorphous/ granular material accompanied by vesicular structures and neurofilaments. The results of the present study have revealed that the pathological features of Bunina bodies in ALS-G are identical to those seen in classical ALS. These findings strongly suggest that a similar degenerative process occurs in the spinal anterior horn cells in both ALS-G and classical ALS.

Adult↗
PubMed1998

Ultrastructure of regions containing homologous loci in polytene chromosomes of Drosophila melanogaster and Drosophila subobscura.

We have used a new approach involving in situ hybridisation and electron microscopy to establish ultrastructural homologies between polytene chromosome regions of Drosophila melanogaster and Drosophila subobscura. Twelve probes were chosen to cover all the chromosomal elements: the myospheroid gene, the collagen type IV gene, the collagen-like gene, the w26 homeobox gene, the beta3 tubulin gene, the kinesin heavy chain gene, the tryptophan hydrolase gene, the Hsp82, Hsp22-26 and Hsp23-28, Hsp68, Hsp70 genes and the beta unit of the F0-F1 ATPase gene. Most of these loci were previously undescribed in D. subobscura and imprecisely located in D. melanogaster. We have demonstrated here, by an ultrastructural analysis of each chromosomal region, that homologous genetic loci tend to show a similar ultrastructure in the two species. With a few exceptions, the structural homology extends to the chromosomal regions surrounding the loci. In some cases, however, no structurally recognisable homology can be seen either in the locus or in its flanking regions.

Animals↗
PubMed2004

A clinicopathologic case report on macular hole associated with von Hippel-Lindau disease: a novel ultrastructural finding of wormlike, wavy tangles of filaments.

BACKGROUND: We describe a novel ultrastructural finding observed in an epiretinal membrane excised from a patient with von Hippel-Lindau disease. METHODS: This interventional case report presents a 45-year-old woman who noted decreased vision in her right eye and was referred for treatment of a macular hole secondary to von Hippel-Lindau disease. Blindness had occurred previously in the left eye because of exudative retinal detachment. Funduscopic examination revealed a macular hole associated with a delicate epiretinal membrane, multiple retinal angiomas, and multiple old laser scars. Vitrectomy was performed in her right eye. The epiretinal membrane was peeled off and processed for light and electron microscopy. RESULTS: Postoperatively the macular hole was successfully closed, and vision recovered to 20/20 from 20/40. In the excised epiretinal membrane, flattened glial cells and extracellular matrix containing fibrous elements formed a multilayered pattern. Ultrastructurally, the fibrous elements appeared as wormlike, wavy tangles of filaments (WWTF) with an orientation parallel to the surface of the epiretinal membrane. Just above the WWTF, flattened glial cells frequently extended thin cytoplasmic processes with pinocytotic vesicles. CONCLUSION: The ultrastructure suggested that retinal glial cells had induced a remodeling of the collagenous stroma in the posterior vitreous cortex, resulting in tangential macular traction.

Basement Membrane↗
PubMed2001

Histoenzymological and ultrastructural changes in lateral muscle fibers of Oreochromis niloticus (Teleostei: Cichlidae) after local injection of veratrine.

The effects of veratrine have been investigated in mammalian, amphibian, and crustacean muscle, but not in fish. In this work, the action of veratrine was studied in the lateral muscle of the freshwater teleost Oreochromis niloticus after intramuscular injection. Histoenzymological typing and electron microscopy of muscle fibers before and 15, 30, and 60 min after veratrine injection (10 ng/kg fish) were used to indirectly assess the morphological changes and the oxidative and m-ATPase activities. In some cases, muscles were pretreated with tetrodotoxin to determine whether the ultrastructural changes were the result of Na(+) channel activation by veratrine. Veratrine altered the metabolism of fibers mainly after 30 min. Oxidative fibers showed decreased NADH-TR activity, whereas that of glycolytic and oxidative-glycolytic type fibers increased. There was no change in the m-ATPase activity of the three fiber types, except at 60 min postveratrine, when a novel fiber type, which showed no reversal after acidic and alkaline preincubations, appeared. Ultrastructural damage involved sarcomeres, myofibrils, and mitochondria, but the T-tubules remained intact. Pretreatment with tetrodotoxin (1 ng/ml) prevented the ultrastructural changes caused by veratrine. These results show that in fish skeletal muscle veratrine produces some effects that are not seen in mammalian muscle.

Adenosine Triphosphatases↗
PubMed2004

The functional architecture of the nucleus as analysed by ultrastructural cytochemistry.

Ultrastructural cytochemistry has been, for many years now, a major tool for investigating structure-function relationships in the cell nucleus. It has been essential in approaching the roles which different nuclear structural constituents can play in nuclear functions. This article briefly summarises transmission electron microscopic studies aimed at characterising in situ nuclear architectural domains and their involvement in main nuclear functions, such as DNA replication, hnRNA transcription and pre-mRNA processing. It discusses the importance of ultrastructural cytochemistry in high resolution analyses of intranuclear distribution of chromatin domains and their topological relationships with other structural interphase nuclear constituents. It puts forward the central role of the perichromatin region as a functional nuclear domain. Finally, it attempts to critically evaluate some future applications of ultrastructural investigations of the nucleus and stresses the importance of combining them with light microscopic analyses of living cells.

Animals↗
PubMed1998

A new method for flat-embedding large native cryostat sections for targeting small preneoplastic lesions in comparative ultrastructural and ultracytochemical investigations.

Ultrastructural studies of rare and small cellular lesions in pathologically altered tissue are difficult to perform by applying conventional electron microscopic preparation. The search for lesions, often consisting of only a few cells in randomly obtained small specimen blocks, is time consuming and often without success. The methodological requirements for comparative enzyme cytochemical and morphological studies, i.e., preservation of both enzyme activity and ultrastructure, are divergent. By processing large native cryostat sections for electron microscopy, small preneoplastic focal lesions were successfully targeted in liver and kidney. Glucose-6-phosphatase, alkaline phosphatase, acid phosphatase, catalase, and cytochrome c oxidase activities were distinctly localized to endoplasmic reticulum, canalicular membrane, lysosomes, peroxisomes, and mitochondria, respectively, in the morphologically altered cells. Fixation of serial cryostat sections and enzyme reactions were both carried out through a semipermeable membrane except those for cytochrome c oxidase, which was demonstrated after fixation through the membrane by floating the section in incubation medium containing cytochrome c. Thereafter, the sections were flat embedded and polymerized between epoxy resin disks and aluminum dishes fitting exactly together. The objects of interest were identified in the light microscope, cut out, and reembedded in reversed gelatine capsules. By using this technique an ultrastructural preservation was achieved similar to that seen after immersion fixation. The enzyme activities were clearly localized without diffusion of the reaction product or unspecific deposits. The procedure permits precise targeting and complex studies of rare and small lesions, and opens new perspectives for the use of cryo-preserved tissue.

Animals↗
PubMed2002

Toker cells are probably precursors of Paget cell carcinoma: a morphological and ultrastructural description.

The present paper documents an investigation of the morphology, immunohistochemistry, and ultrastructure of Toker cells (TC), aiming for a better definition of these elements and better understanding of their histogenesis. We studied 12 nipples removed for nipple adenoma from twelve patients and a case of supernumerary nipple. In addition four cases of Paget's carcinoma (PC) restricted to the nipple without underlying tumor were studied for comparison. All cases were stained with hematoxylin and eosin (H&E), Alcian blue pH 2.5 and periodic acid-Schiff (PAS) preceded by diastase digestion and with immunohistochemistry using antisera anti cytokeratin 7, cytokeratin 20, protein S100, GCDFP-15, c-Erb-B2, CAM 5.2, and epithelial membrane antigen (EMA). Two cases from the nipple adenoma series were studied by electron microscopy. In seven cases within the series of 12 nipple adenomas as well as in the case of supernumerary nipple, keratin 7 antibody highlighted numerous cells located within the nipple epidermis which in three cases showed dendritic processes. These same elements were also positive with CAM 5.2. All these same elements were negative with Alcian Blue (AB), PAS and the other antisera employed. Ultrastructural examination demonstrated that these cells differed from keratinocytes while they presented the same features as the glandular cells seen in the related nipple adenoma. The cells constituting Paget's carcinoma showed more irregular nuclei and were more easily seen in the context of the epidermis. The immunocytochemical profile of the cancer cells was similar to that of TC, but in addition the neoplastic cells were c-Erb-B2 and EMA positive in all cases, and one case also displayed numerous cells immunoreactive with anti GCDFP-15 antibody. Keratin 7 highlighted dendritic cells in two cases and AB, PAS was negative in all patients. The immunocytochemical profile and the ultrastructural features of TC are similar to those of the glandular cells constituting the ducts and the adenoma. These findings together with the localization of TC near or around the openings of the lactiferous sinuses indicate that TC might be ductal cells with a dendritic aspect and migrate through the galactophorous ostia. PC cells not related to ductal carcinomas have a similar but not superimposable immunohistochemical profile to TC, and in two cases the neoplastic elements were also dendritic which suggests that these same cells are likely to be the neoplastic counterpart of TC.

Adenoma↗
PubMed2003

Pulmonary well-differentiated fetal adenocarcinoma expressing lineage-specific transcription factors (TTF-1 and GATA-6) to respiratory epithelial differentiation: an immunohistochemical and ultrastructural study.

A case of pulmonary well-differentiated fetal adenocarcinoma was examined with conventional histological, immunohistochemical, and ultrastructural studies that revealed the distribution of lineage-specific transcription factors (TTF-1 and GATA-6). The patient was a 33-year-old Japanese woman, who underwent resection of the right lower lobe for the lung tumor. The tumor demonstrated an organized histology mimicking the epithelial differentiation of fetal lung with peculiar glands and moruloid cell nests, without mesenchymal proliferation. Adenocarcinoma cells forming the atypical glands were similar to the epithelial cells of the branching tubules in the pseudo glandular stage of the fetal lung. Distribution of TTF-1 was observed in many of the nuclei of the adenocarcinoma cells forming the glands. Tumor cells in the morula were primitive epithelial cells with some immunohistochemical neuroendocrine cell differentiation and some of them showed GATA-6-positive stains in the nuclei. In the ultrastructural study, adenocarcinoma cells showed little differentiation toward mucous cells and ciliated cells. Neuroendocrine granules were seen in a few tumor cells in the morula. In the present case, tumor cells forming the peculiar histological, molecular, and ultrastructural constructions showed partial and incomplete mimicry of the morphogenesis of respiratory epithelium.

Adenocarcinoma↗
PubMed2000

The protective role of atorvastatin on function, structure and ultrastructure in the aorta of dyslipidemic rabbits.

Responses to both an endothelium-dependent (acetylcholine 10(-9)-10(-5) mol/l) and an endothelium-independent vasodilator (sodium nitroprusside 10(-10)-10(-6) mol/l) were studied in aortic rings from rabbits fed or not with a diet containing 0.5% cholesterol plus 14% coconut oil for 14 weeks and treated or not with atorvastatin (2.5 mg/kg/day). Morphometric and ultrastructure analyses were also performed. Rabbits fed the dyslipidemic diet presented higher plasma cholesterol and triglyceride concentrations than controls (P < 0.05). This was associated with intima-media thickening and, consequently, aortic stenosis (29 +/- 3%) since vessel cross-sectional area did not change. Endothelial cells presented numerous alterations in dyslipidemic rabbits. Atorvastatin treatment only reduced plasma levels in dyslipidemic rabbits (P < 0.05), which were nevertheless higher than those of controls. In addition, it prevented the reduction in acetylcholine relaxation in hypercholesterolemic animals. Atorvastatin administration also enhanced the response to acetylcholine in rabbits fed a control diet. Likewise, atorvastatin treatment reduced lesion area and consequently increased aortic lumen in dyslipidemic rabbits but did not modify media thickening. It also prevented the majority of the ultrastructural changes observed in endothelial cells. In conclusion, chronic atorvastatin treatment exerts a protective role in vascular function, structure and ultrastructure even in the presence of high cholesterol and triglyceride plasma levels.

Animals↗
PubMed2001

Comparative ultrastructural study of cytotoxic granules in nasal natural killer cell lymphoma, intestinal T-cell lymphoma, and anaplastic large cell lymphoma.

Comparative immunohistochemical and ultrastructural studies were performed on five nasal natural killer (NK) cell lymphoma cases, two intestinal T-cell lymphoma cases, and eight anaplastic large cell lymphoma (ALCL) cases to clarify morphological differences in cytotoxic granules among these cytotoxic lymphomas. Nasal NK-cell lymphomas and intestinal T-cell lymphomas had fine azurophilic granules and displayed dot-like immunostaining of granzyme B- and T-cell intracellular antigen 1 (TIA-1), predominantly in the central area of the cytoplasm. Ultrastructurally, these NK-cell lymphomas and intestinal T-cell lymphomas had two types of cytotoxic granules, type-I granules (dense core granules) and type-II granules (multivesicular bodies), which have been demonstrated in normal large granular lymphocytes in peripheral blood. However, ALCLs did not have azurophilic granules, and only type-II cytotoxic granules were found ultrastructurally, even though they showed similar dot-like immunostained patterns of granzyme B and TIA-1, as seen in NK-cell lymphomas and intestinal T-cell lymphomas. Immunoelectron microscopy revealed that TIA-1 was primarily located at the periphery of the cytoplasmic granules in the NK-cell lymphoma and ALCL cases. These findings suggest that malignant lymphomas with a cytotoxic phenotype can be divided into two types, (azurophilic granule)+, (type-I granule)+, (type-II granule)+ lymphomas and (azurophilic granule)-, (type-I granule)-, (type-II granule)+ lymphomas.

Adult↗
PubMed2002

Ultrastructure of spermiogenesis and spermatozoa of Taenia parvaBaer, 1926 (Cestoda, Cyclophyllidea, Taeniidae), a parasite of the common genet ( Genetta genetta).

We studied the ultrastructure of spermiogenesis and of the mature spermatozoon of Taenia parva, an intestinal cestode of the common genet, Genetta genetta. Spermiogenesis in T. parva is characterized by the growth of the axoneme externally to a cytoplasmic extension. After a slight rotation, the free flagellum fuses with the cytoplasmic extension. This pattern corresponds to type III spermiogenesis according to the scheme proposed by Bâ and Marchand. The zone of differentiation lacks both striated roots associated with the centrioles and the intercentriolar body between them. Nevertheless, the flagellar rotation of about 45 degrees is observed in this species. On the other hand, the mature spermatozoon of T. parva, as in other cestodes, is filiform, tapered at both extremities and lacks mitochondria. The presence of a single crest-like body, periaxonemal sheath, and transverse intracytoplasmic walls are also characteristic ultrastructural features. The pattern of spermiogenesis and the ultrastructural organization of the spermatozoon of T. parva are compared with the available data on cyclophyllideans and, in particular, species of the family Taeniidae.

Animals↗